In a technical field of electricity storage devices, a development is being made for a current interruption device that interrupts current flowing through terminals (positive terminal and negative terminal) when an electricity storage device is over-charged or a short circuiting is generated therein. The current interruption device is arranged between a terminal and a collector tab (positive collector tab or negative collector tab). Japanese Patent Application Publication No. 2012-38529 discloses a current interruption device in which a conducting plate connected to a collector tab and a deformable plate connected to a terminal are bonded. When pressure inside a casing of an electricity storage device rises and exceeds a predetermined value, the current interruption device is operated and the deformable plate separates away from the conduction plate. As a result, current between the terminal and the conduction plate is interrupted.